U.S. patent application number 16/647014 was filed with the patent office on 2020-08-13 for lithium-sulfur rechargeable battery.
This patent application is currently assigned to QATAR FOUNDATION FOR EDUCATION, SCIENCE AND COMMUNITY DEVELOPMENT. The applicant listed for this patent is QATAR FOUNDATION FOR EDUCATION, SCIENCE AND COMMUNITY DEVELOPMENT. Invention is credited to ALI ABOUIMRANE, ILIAS BELHAROUAK, MARINE BEATRICE CUISINIER.
Application Number | 20200259207 16/647014 |
Document ID | 20200259207 / US20200259207 |
Family ID | 1000004807618 |
Filed Date | 2020-08-13 |
Patent Application | download [pdf] |
![](/patent/app/20200259207/US20200259207A1-20200813-D00000.png)
![](/patent/app/20200259207/US20200259207A1-20200813-D00001.png)
![](/patent/app/20200259207/US20200259207A1-20200813-D00002.png)
![](/patent/app/20200259207/US20200259207A1-20200813-D00003.png)
![](/patent/app/20200259207/US20200259207A1-20200813-D00004.png)
![](/patent/app/20200259207/US20200259207A1-20200813-D00005.png)
![](/patent/app/20200259207/US20200259207A1-20200813-D00006.png)
United States Patent
Application |
20200259207 |
Kind Code |
A1 |
CUISINIER; MARINE BEATRICE ;
et al. |
August 13, 2020 |
LITHIUM-SULFUR RECHARGEABLE BATTERY
Abstract
The lithium-sulfur rechargeable battery (10) includes a negative
electrode (14) formed from a composite of sulfurized
polyacrylonitrile (SPAN), carbon black and carbon nanofibers coated
on an aluminum substrate. The negative electrode (14), a
corresponding positive electrode (16), an electrolyte (20) and a
separator (18) are each disposed within a cell housing (12). The
positive electrode (16) is formed from an alkali metal, an alkaline
earth metal or salts thereof. The alkali metal of the positive
electrode (16) may be, for example, lithium, sodium, potassium or
cesium, and the alkaline earth metal of the positive electrode (16)
may be, for example, magnesium, calcium or barium. Alternatively,
the positive electrode (16) may be formed from aluminum, silver,
zinc, hydrogen or salts thereof. The electrolyte (20) is formed
from an alkali metal salt dissolved in an organic solvent.
Inventors: |
CUISINIER; MARINE BEATRICE;
(DOHA, QA) ; ABOUIMRANE; ALI; (DOHA, QA) ;
BELHAROUAK; ILIAS; (DOHA, QA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
QATAR FOUNDATION FOR EDUCATION, SCIENCE AND COMMUNITY
DEVELOPMENT |
Washington |
DC |
US |
|
|
Assignee: |
QATAR FOUNDATION FOR EDUCATION,
SCIENCE AND COMMUNITY DEVELOPMENT
DOHA
QA
|
Family ID: |
1000004807618 |
Appl. No.: |
16/647014 |
Filed: |
September 11, 2018 |
PCT Filed: |
September 11, 2018 |
PCT NO: |
PCT/US2018/050523 |
371 Date: |
March 12, 2020 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
62557592 |
Sep 12, 2017 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01M 4/602 20130101;
H01M 4/133 20130101; H01M 4/505 20130101; H01M 4/621 20130101; H01M
4/136 20130101; H01M 4/525 20130101; H01M 10/0525 20130101 |
International
Class: |
H01M 10/0525 20060101
H01M010/0525; H01M 4/60 20060101 H01M004/60; H01M 4/505 20060101
H01M004/505; H01M 4/525 20060101 H01M004/525; H01M 4/136 20060101
H01M004/136; H01M 4/62 20060101 H01M004/62; H01M 4/133 20060101
H01M004/133 |
Claims
1. A rechargeable battery, comprising a secondary battery having: a
negative electrode comprising a conductive polymer matrix having
elemental sulfur covalently bound thereto; a positive electrode
having an intercalated metal selected from the group consisting of
an alkali metal, an alkaline earth metal, and salts thereof; and an
electrolyte, the negative electrode and the positive electrode
being at least partially disposed in the electrolyte, the
electrolyte comprising an alkali metal salt dissolved in an organic
solvent.
2. The rechargeable battery according to claim 1, wherein said
negative electrode comprises a composite of sulfurated
polyacrylonitrile, carbon black, and carbon nanofibers cast onto an
aluminum support.
3. The rechargeable battery as recited in claim 1, wherein the
alkali metal is selected from the group consisting of lithium,
sodium, potassium and cesium.
4. The rechargeable battery as recited in claim 1, wherein the
alkaline earth metal is selected from the group consisting of
magnesium, calcium, and barium.
5. The rechargeable battery according to claim 1, wherein said
alkali metal comprises lithium.
6. The rechargeable battery according to claim 5, wherein said
intercalated metal comprises a lithium oxide having a spinel
structure, a layered lithium oxide, or a lithium
orthophosphate.
7. The rechargeable battery according to claim 1, wherein said
positive electrode has a voltage of at least 4 Volts relative to a
Li.sup.+/Li electrode.
8. The rechargeable battery as recited in claim 3, wherein the
alkali metal salt is selected from the group consisting of a
lithium salt, a sodium salt, a potassium salt and a cesium
salt.
9. The rechargeable battery as recited in claim 1, wherein the
electrolyte comprises lithium hexafluorophosphate dissolved in a
mixture of ethylene carbonate and diethyl carbonate.
10. The rechargeable battery as recited in claim 1, further
comprising a separator positioned between the negative electrode
and the positive electrode.
11. The rechargeable battery as recited in claim 10, wherein the
separator comprises a polypropylene film.
12. A lithium-sulfur rechargeable battery, comprising a secondary
battery having: a negative electrode comprising a composite of
sulfurated polyacrylonitrile, carbon black, and carbon nanofibers
cast onto an aluminum support; a positive electrode having an
intercalated lithium compound selected from the group consisting of
a lithium oxide having a spinel structure, a layered lithium oxide,
or a lithium orthophosphate; and an electrolyte, the negative
electrode and the positive electrode being at least partially
disposed in the electrolyte, the electrolyte comprising an alkali
metal salt dissolved in an organic solvent.
13. The lithium-sulfur rechargeable battery according to claim 12,
wherein said positive electrode has a voltage of at least 4 Volts
relative to a Li.sup.+/Li electrode.
14. The lithium-sulfur rechargeable battery according to claim 12,
wherein said intercalated lithium compound is a lithium oxide
having a spinel structure selected from the group consisting of
LiNi.sub.0.5Mn.sub.1.5O.sub.4 and
LiNi.sub.0.4Mn.sub.1.6O.sub.4.
15. The lithium-sulfur rechargeable battery according to claim 12,
wherein said intercalated lithium compound is a layered lithium
oxide having the formula xLi.sub.2MnO.sub.3.(1-x)LiMO.sub.2 where M
is Mn, Ni, or Co and 0<x<1.
16. The lithium-sulfur rechargeable battery according to claim 12,
wherein said intercalated lithium compound is an orthophosphate
selected from the group consisting of LiCoPO.sub.4 and
LiNiPO.sub.4.
17. A rechargeable battery, comprising a secondary battery having:
a negative electrode comprising a composite of sulfurized
polyacrylonitrile, carbon black and carbon nanofibers coated on an
aluminum substrate; a positive electrode comprising a metal
selected from the group consisting of aluminum, silver, zinc,
hydrogen, and salts thereof; and an electrolyte comprising an
alkali metal salt dissolved in an organic solvent, the positive and
negative electrodes being at least partially disposed in the
electrolyte.
18. The rechargeable battery as recited in claim 17, wherein the
electrolyte comprises lithium hexafluorophosphate dissolved in a
mixture of ethylene carbonate and diethyl carbonate.
Description
TECHNICAL FIELD
[0001] The disclosure of the present patent application relates
generally to rechargeable batteries, and particularly to a
lithium-sulfur rechargeable battery having a sulfurated composite
material (referred to herein as SPAN) as the negative electrode
material and a high-voltage alkali intercalation material as the
positive electrode.
BACKGROUND ART
[0002] There is great interest in lithium-sulfur (Li/S)
rechargeable batteries, due primarily to their high theoretical
capacity 1672 mA h/g and energy density 2500 W h/kg. Sulfur (S) is
normally considered as the positive electrode material, with
metallic lithium used as the negative electrode. The high capacity
is based on the conversion reaction of elemental sulfur to form the
lithium sulfide (Li.sub.2S) by reversibly incorporating two
electrons per sulfur atom at an electrochemical potential around
2.1 V vs. Li.sup.+/Li. This is an order of magnitude higher than
that of current commercial lithium-ion technology. Unfortunately,
Li/S batteries presently have major shortcomings that prevent them
from being commercialized.
[0003] Sulfur is a highly insulating element and needs conductive
electron additives, such as carbon fiber or carbon black, to make
it feasible as an electrode material, thus decreasing the practical
energy density that can be obtained from the system. Additionally,
the intermediate lithium polysulfides formed during battery cycling
are soluble in the electrolyte and can diffuse or migrate to the
lithium negative electrode, which induces the so-called "shuttle
mechanism" within the electrochemical cell.
[0004] The formation of soluble, strongly nucleophilic
intermediates during charge and discharge between sulfur and
Li.sub.2S is the main cause of Li/S battery failure and the main
impediment for its commercialization.
[0005] Thus, a lithium-sulfur rechargeable battery solving the
aforementioned problems is desired.
DISCLOSURE
[0006] The lithium-sulfur rechargeable battery is a secondary
battery that includes a negative electrode formed from a composite
of sulfurated polyacrylonitrile (SPAN), carbon black and carbon
nanofibers coated on an aluminum substrate. The positive electrode
is a strongly oxidizing intercalation material (e.g., a layered
compound or spinel structure, or orthophosphates) formed from an
alkali metal, an alkaline earth metal, or salts thereof. The alkali
metal of the positive electrode may be, for example, lithium,
sodium, potassium or cesium, and the alkaline earth metal of the
positive electrode may be, for example, magnesium, calcium or
barium. Other metals that might be used in the positive electrode
include aluminum, silver, and zinc. Potentially, even hydrogen
might be used. The metal of the positive electrode is selected such
that the positive active material thereof has an electrochemical
potential of at least 4.0 V relative to the alkali metal, and more
preferably at least 4.5 V relative to the alkali metal. The
electrolyte is formed from an alkali metal salt dissolved in an
organic solvent. The alkali salt may be, for example, a lithium
salt, a sodium salt, a potassium salt or a cesium salt. The
positive and negative electrodes, an electrolyte, and a separator
are each disposed within a cell housing.
[0007] These and other features of the present disclosure will
become readily apparent upon further review of the following
specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a schematic diagram of a lithium-sulfur
rechargeable battery.
[0009] FIG. 2A is a plot comparing the capacity cycling performance
of a rechargeable battery (SPAN/NCA) having a SPAN negative
electrode and a lithium-nickel-carbon-aluminum
(LiNi.sub.0.8Co.sub.0.15Al.sub.0.05O.sub.2) positive electrode
against the capacity cycling performance of a conventional prior
art rechargeable battery (Li/SPAN) having a lithium negative
electrode and a SPAN-positive electrode.
[0010] FIG. 2B is a plot comparing the capacity cycling performance
of a rechargeable battery having a lithiated graphite (Li.sub.xC)
negative electrode and a SPAN positive electrode (Li.sub.xC/SPAN),
against the capacity cycling performance of the conventional prior
art rechargeable battery with a lithium negative electrode and a
SPAN-based positive electrode (Li/SPAN).
[0011] FIG. 3A is a plot showing the galvanostatic profile for a
rechargeable battery having a metallic lithium negative electrode
and a SPAN positive electrode (SPAN/Li).
[0012] FIG. 3B is a plot showing the galvanostatic profile for a
rechargeable battery having a SPAN negative electrode and a
lithium-nickel-carbon-aluminum
(LiNi.sub.0.8Co.sub.0.15Al.sub.0.05O.sub.2) positive electrode
(NCA/SPAN).
[0013] FIG. 4A is a plot comparing the specific capacity between a
conventional prior art rechargeable battery having a
LiNi.sub.0.5Mn.sub.1.5O.sub.4 (LMNO) positive electrode and a
lithium titanate (LTO) negative electrode (LMNO/LTO), against the
specific capacity of a rechargeable battery having an LMNO positive
electrode and a SPAN negative electrode (LMNO/SPAN) normalized by
the mass of the LMNO for the first charge/discharge cycle.
[0014] FIG. 4B is a plot comparing the specific energy between the
conventional prior art rechargeable battery having a
LiNi.sub.0.5Mn.sub.1.5O.sub.4 (LMNO) positive electrode and a
lithium titanate (LTO) negative electrode (LMNO/LTO), against the
specific capacity of a rechargeable battery having an LMNO positive
electrode and a SPAN negative electrode (LMNO/SPAN) for the first
charge/discharge cycle, where the specific energy is normalized by
the mass of active materials in both electrodes.
[0015] FIG. 4C is a plot comparing the specific capacity as a
function of the number of charge/discharge cycles of a conventional
prior art rechargeable battery having a
LiNi.sub.0.5Mn.sub.1.5O.sub.4 (LMNO) positive electrode and a
lithium titanate (LTO) negative electrode (LMNO/LTO), against a
rechargeable battery having an LMNO positive electrode and a SPAN
negative electrode (LMNO/SPAN), where the specific capacity is
normalized by the mass of the LMNO.
[0016] FIG. 4D is a plot comparing the specific energy as a
function of the number of charge/discharge cycles between a
conventional prior art rechargeable battery having a
LiNi.sub.0.5Mn.sub.1.5O.sub.4 (LMNO) positive electrode and a
lithium titanate (LTO) negative electrode (LMNO/LTO), against a
rechargeable battery having an LMNO positive electrode and a SPAN
negative electrode (LMNO/SPAN), where the specific energy is
normalized by the mass of active materials in both electrodes.
[0017] FIG. 5 is a chart comparing calculations of the specific
energy theoretically achievable with the SPAN composite negative
electrode against that of conventional graphite and lithium
titanate (LTO) negative electrodes, shown for positive electrodes
formed from either 5 V spinel LiNi.sub.0.5Mn.sub.1.5O.sub.4 or
Li-rich layered Li.sub.1.2Ni.sub.0.3Mn.sub.0.6O.sub.2.1.
[0018] Similar reference characters denote corresponding features
consistently throughout the attached drawings.
BEST MODE(S) OF CARRYING OUT THE INVENTION
[0019] The lithium-sulfur rechargeable battery 10 includes a
negative electrode 14 formed from a composite of sulfurized
polyacrylonitrile (SPAN), carbon black and carbon nanofibers coated
on an aluminum substrate (i.e., an aluminum current collector). As
shown in FIG. 1, the negative electrode 14, a corresponding
positive electrode 16, an electrolyte 20, and a separator 18 are
each disposed within a cell housing 12. The positive electrode 16
is a strongly oxidizing intercalation material (e.g., a layered
compound or spinel structure, or orthophosphates) formed from an
alkali metal, an alkaline earth metal or salts thereof. The alkali
metal of the positive electrode 16 may be, for example, lithium,
sodium, potassium or cesium, and the alkaline earth metal of the
positive electrode 16 may be, for example, magnesium, calcium or
barium. Alternatively, the positive electrode 16 may be formed from
aluminum, silver, or zinc, or in some embodiments, from hydrogen.
For a lithium-based positive electrode, the positive electrode 16
may be formed from spinel-type lithium oxides (e.g.,
(LiNi.sub.0.5Mn.sub.1.5O.sub.4 or LiNi.sub.0.4Mn.sub.1.6O.sub.4),
layered lithium oxides (e.g., of the type
xLi.sub.2MnO.sub.3.(1-x)Li(Mn, Co, Ni)O.sub.2, or lithium
orthophosphates (e.g., LiCoPO.sub.4 or LiNiPO.sub.4). The metal of
the positive electrode 16 is selected such that the positive active
material thereof has an electrochemical potential of at least 4.0 V
relative to the alkali metal, and more preferably at least 4.5 V
relative to the alkali metal.
[0020] The electrolyte 20 is formed from an alkali metal salt
dissolved in an organic solvent. The alkali salt may be, for
example, a lithium salt, a sodium salt, a potassium salt or a
cesium salt. For example, the electrolyte used in testing, as will
be described in detail below, was a 1 M solution of lithium
hexafluorophosphate (LiPF.sub.6) in a mixture of ethylene carbonate
(EC) and diethyl carbonate (DEC). The separator 18 used in testing
was a 25 .mu.m thick polypropylene film.
[0021] In order to prepare the negative electrode 14, 1 g of
polyacrylonitrile (PAN) was mixed with 0.05 g of multi-walled
carbon nanotubes, 0.05 g of Ketjenblack carbon powder, and 5 g of
elemental sulfur. The mixture was heated under inert atmosphere
(nitrogen gas) up to 550.degree. C. and left to react for six
hours. After cooling down, the SPAN composite material obtained was
purified by heating under vacuum at 300.degree. C. This SPAN
composite was further processed into the negative electrode 14 by
mixing the SPAN (80 wt %) with carbon black (5 wt %), hydrophilic
carbon nanofibers (5 wt %) and a polyacrylic acid-polyvinyl acid
binder (10 wt %) in water. The slurry was cast into a film onto an
aluminum current collector, and the electrode laminate was then
dried at 100.degree. C. for four hours, and then at 150.degree. C.
for one additional hour.
[0022] Other suitable transition metal compounds that may be used
with lithium in the positive electrode include spinel-type oxides
(LiNi.sub.0.5Mn.sub.1.5O.sub.4 and LiNi.sub.0.4Mn.sub.1.6O.sub.4),
layered oxides of the type
xLi.sub.2MnO.sub.3.(1-x)Li(Mn,Ni,Co)O.sub.2 (also expressed as
xLi.sub.2MnO.sub.3-(1-x)LiMO.sub.2 where M is Mn, Ni, or Co and
0<x<1), and orthophosphates (LiCoPO.sub.4 or
LiNiPO.sub.4).
[0023] FIG. 2A compares the capacity cycling performance of a
rechargeable battery having a lithium-nickel-carbon-aluminum
(LiNi.sub.0.8Co.sub.0.15Al.sub.0.05O.sub.2) positive electrode and
the SPAN composite negative electrode 14 (SPAN/NCA), against the
capacity cycling performance of a conventional prior art
rechargeable battery having a lithium negative electrode and a
SPAN-based positive electrode (Li/SPAN). Similarly, FIG. 2B
compares the capacity cycling performance of a rechargeable battery
having a lithiated graphite (Li.sub.xC) negative electrode and a
SPAN composite positive electrode (Li.sub.xC/SPAN), against the
capacity cycling performance of the conventional prior art
rechargeable battery with a lithium negative electrode and a
SPAN-based positive electrode (Li/SPAN). The current rate used was
C/5, i.e., 335 mA/g.sub.s. FIGS. 2A and 2B show that using lithium
as the negative electrode has an adverse effect on the cycling life
of the rechargeable battery. This is aggravated in conventional
lithium ion rechargeable batteries by the use of too much lithium
(usually greater than 300% more than needed) and by the use of too
much electrolyte (usually more than ten times the amount needed).
These factors decrease the specific energy (i.e., W h/kg) and add
excess weight to the battery. The lithium metal carries safety
risks, and the electrolyte decomposes at the surface of the lithium
at every charge/discharge cycle.
[0024] By contrast, as shown in FIGS. 2A and 2B, the SPAN
electrode, whether used as the negative electrode with layered or
spinel positive electrode (FIG. 2A), or as the positive electrode
with a lithiated graphite negative electrode (FIG. 2B) and a
reasonable amount of electrolyte, results in extended cycling
performance. Although the lithiated graphite as negative electrode
with SPAN as positive electrode results in reasonable recycling
performance, there are problems associated with the use of
lithiated graphite as the negative electrode. First, neither
graphite nor SPAN host alkali cations in their pristine form, and
therefore one or the other would need to be pre-intercalated under
inert atmosphere. Second, lithiated graphite has low intercalation
potential and the associated risk of lithium plating. Third, the
output voltage of a graphite/SPAN cell is rather low (around 1.5
V), and there is not much room for improvement.
[0025] Using SPAN as the negative electrode allows assembling full
Li-ion cells with high voltage positive electrode material. FIG. 3A
illustrates the galvanostatic profile for a rechargeable battery
having a metallic lithium negative electrode and a SPAN composite
positive electrode (SPAN/Li). On the other hand, FIG. 3B
illustrates the galvanostatic profile for a rechargeable battery
having a lithium-nickel-carbon-aluminum
(LiNi.sub.0.5Co.sub.0.15Al.sub.0.05O.sub.2) positive electrode and
a SPAN composite negative electrode (NCA/SPAN). For both cases, the
current rates are C/20; i.e., 84 mA/g, for the first cycle, and
C/10; i.e., 168 mA/g, for the second cycle. It is noted that the
output voltage in FIG. 3B is close to the output voltage in FIG.
3A, which suggests that the
LiNi.sub.0.8Co.sub.0.15Al.sub.0.05O.sub.2 electrode has a voltage
at the lower end of the scale as compared to metallic lithium.
Other intercalated lithium electrodes used as positive electrodes
have a higher voltage differential compared to lithium metal and
will produce cell output voltages greater than 2.8 V.
[0026] FIGS. 4A-4D compare the cycling performance between a
rechargeable battery having a LiNi.sub.0.5Mn.sub.1.5O.sub.4 (LMNO)
positive electrode and a lithium titanate (LTO) negative electrode
(LMNO/LTO) against the cycling performance of a rechargeable
battery having a LiNi.sub.0.5Mn.sub.1.5O.sub.4(LMNO) positive
electrode and a SPAN composite negative electrode (LMNO/SPAN). FIG.
4A shows the comparison in terms of first cycle galvanostatic cell
voltage as a function of specific capacity, normalized by the mass
of LMNO, and FIG. 4B shows the comparison in terms of first cycle
galvanostatic cell voltage as a function of specific energy,
normalized by the mass of active materials in both electrodes (AM).
Cyclability is shown over 50 cycles in FIG. 4C, showing the
evolution of specific capacity, normalized by the mass of LMNO, as
a function of the number of cycles, and in FIG. 4D, showing the
evolution of specific energy, normalized by the mass of active
materials in both electrodes (AM), as a function of the number of
cycles. For all cases, the current rates are C/10, i.e., 15
mA/g.sub.LMNO for the first cycle, and C/5, i.e., 30 mA/g.sub.LMNO
for the following cycles. In FIG. 4A, the LMNO/LTO battery only
shows 59% Coulombic efficiency at the first cycle, whereas the
LMNO/SPAN battery has a 74% efficiency. As seen in FIG. 4B, the
LMNO/LTO battery only has an 83 Wh/kg reversible specific energy,
while the LMNO/SPAN battery has a reversible specific energy of 208
Wh/kg. There is an approximately 10-fold increase in specific
capacity when using the SPAN composite negative electrode.
Similarly, there is approximately a two-fold increase in specific
energy when using the SPAN composite negative electrode.
[0027] FIG. 5 shows the specific energy theoretically achievable
with the SPAN composite negative electrode compared against that of
conventional graphite and lithium titanate (LTO) negative
electrodes, shown for positive electrodes formed from 5 V spinel
LiNi.sub.0.5Mn.sub.1.5O.sub.4 or the lithium-rich layered
Li.sub.1.2Ni.sub.0.3Mn.sub.0.6O.sub.2.1 electrode. Although the
overall specific energy remains lower when the SPAN negative
electrode is used compared to a graphite negative electrode, the
reactivity of full cells is expected to be greatly diminished,
especially in the charged state, thus rendering the lithium-sulfur
rechargeable battery a safer alternative. Comparing LTO and
SPAN-based negative electrodes, the two-fold increase in specific
energy observed experimentally (in FIGS. 4A-4D) is also expected
for any high voltage positive electrode material. Additional
benefits expected from the sulfurized polymer compared to LTO are
reduced gassing during cycling, resulting in improved safety, and a
significantly lower production cost.
[0028] It is to be understood that the lithium-sulfur rechargeable
battery is not limited to the specific embodiments described above,
but encompasses any and all embodiments within the scope of the
generic language of the following claims enabled by the embodiments
described herein, or otherwise shown in the drawings or described
above in terms sufficient to enable one of ordinary skill in the
art to make and use the claimed subject matter.
* * * * *